Current Sensing Transformers (CT)

  • Current Sensing Transformers Current Sensing Transformers
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It is common knowledge that we can’t actually see electricity. Rather, we can see and measure how it works. A Current Transformer is one of the important tools used to achieve that measurement.  Current transformers provided by Bicron are designed for common commercial and industrial uses, and also for high-reliability applications that must withstand the demands of rugged environments. Our Current Transformers are best known for high accuracy and longevity.

Applications for Bicron Current Transformers include:
  • Computer Data Centers
  • Energy Monitoring
  • HVAC Monitoring
  • Industrial Control Systems
  • Lighting Control
  • Motor Monitoring
  • Distribution Transformer Monitoring
  • Power Control Panels
  • Breaker Panels
  • Smart Grid Monitoring
  • Power Distribution
  • Power Quality
  • Process Control Systems
  • Residential Energy Monitoring
  • Secondary Metering
  • Revenue Metering SCADA Systems
  • Solar Power Inverter Monitoring
  • Wind Power System Monitoring
  • Geothermal Power Systems


50Hz to 60Hz 3-phase high voltage power harvesting & current sensing transformer assembly. Used for switchgear, power distribution monitoring.                       


Bicron's Multi-Phase Current Transformers for medium voltage, 50Hz to 60Hz, power grid applications are self-powered through energy harvesting. Our CT design senses and powers each phase, and provides power for metering, monitoring, communications and other external electronics. Complete isolation using solid dialectrics makes our device an excellent choice for switchgear applications. Designed and built to meet customer's unique applications. Open frame or fully potted assemblies are available.

Bicron split core Current Transformers offer the best available designs and features that achieve accuracy ranges of class 1.0 or better.  Models include optional split or solid core, miniature CTs, busbar, relay protection, IP68 rated for outdoor use, and more. Select an image below to view the datasheet for that model.
Miniature split core CT
Input 5A to 100A, Output 333m VAC standard
Busbar CT
Standard and custom sizes to 6000A, CAT IV rated
Split core CT
Five window sizes, CAT III rated
Split core CT
Millivolt AC output, 4160 VAC rated, multiple window sizes
Split or solid core CT
Weatherproof; NEMA 6P/IP68W, hinged bar
Relay protection CT
Split Core CT. Up to C800 rating, many sizes available
Relay protection CT
Solid Core CT. Up to C800 rating, many sizes available
Instrument CT
Split or solid core. 600 VAC rated
Medium voltage instrument CT
Split core, 4160VAC applications, window sizes up to 8”x8”
Flexible Rogowski coil
Input current 10A to 100KA, output 250mV, 333mV

Our custom Current Transformer designs are developed to meet unique customer applications.  Our extensive experience includes custom models for high voltage applications such as power distribution sensing and power harvesting. We also offer value-added assembly.  
Please use our Current Transformer Design Worksheet to describe your application requirements for a Bicron modified standard or custom designed Current Transformer.

Visit our Technical Guide for Current Transformers webpage which provides fundamentals for Current Transformer design including technical terminology.

Our standard Current Sensing Transformers include window sizes up to 350 square inches with current ratings up to 10,000A and current ratios from 10:1 to 6000:5. Select models are UL recognized for indoor applications.  See the selection table below for more details.

Advantages of using Bicron Standard Current Sensing Transformers:
  • Low cost AC current sensing
  • Electrically isolated output
  • No external power requirements
  • Safety recognitions
  • Simple electronic interface
  • Small size and weight
  • PCB Mounting
  • Extreme reliability
  • High linearity & repeatability
Bicron’s proven Standard Current Sensing Transformer designs are great starting points for new application requirements. Our “modified standard” program permits us to substantially modify our standard electrical and mechanical specifications without incurring the cost of new product development. This allows you to quickly optimize your system at lower cost with our proven technology.

Selection of Core Materials and Models
Our preferred core material for standard current sensing transformers is Bicron’s Special Permeability (SP), with proven performance features for accuracy, linearity, low-end resolution and temperature sensitivity.  We also offer current sensing transformers made with Grain Oriented Silicon Steel (GOSS), providing good performance at a lower cost.  Bicron’s preferred SP and GOSS materials offer advantages over other typical core materials as represented in the following comparison chart:

                          Core material considerations:
Preferred Core Materials Advantages
 Special Permeability (SP)  Improved performance over wide temp; -35°C - +80°C
 Improved low level performance after exposure to DC shock
 Minimal Phase Angle (Iprimary VS Isecondary) typically less than 1%
 Excellent coupling of primary and secondary currents
 Grain Oriented Silicon Steel (GOSS)  Provides high output voltages suitable for self-powered sensing


Bicron Current Sensing Transformers - Selection Guide     click here to view as pdf

Measurement: inches (mm)     Data subject to change    *UL recognized for indoor applications         Links for Datasheets appear if available

Pinout Options:

Bicron Current Sensing Transformers Performance Characteristics (click here to view PDF):

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